CVE-2021-27457 – Emerson Rosemount X-STREAM Gas Analyzers use we... (How to Fix)

Q: What is the severity of CVE-2021-27457?

CVE-2021-27457 has a CVSS score of 7.5 (HIGH). Emerson Rosemount X-STREAM Gas Analyzers use weak encryption for sensitive data storage, allowing attackers to potentially decrypt and obtain credentials. This affects multiple revisions of these industrial gas analysis devices used in critical infrastructure sectors.

📋 TL;DR

Emerson Rosemount X-STREAM Gas Analyzers use weak encryption for sensitive data storage, allowing attackers to potentially decrypt and obtain credentials. This affects multiple revisions of these industrial gas analysis devices used in critical infrastructure sectors.

💻 Affected Systems

Products:

Emerson Rosemount X-STREAM Gas Analyzer

Versions: Multiple revisions (specific versions not detailed in advisory)

Operating Systems: Embedded/Proprietary

Default Config Vulnerable: ⚠️ Yes

Notes: All default configurations are vulnerable due to inherent weak encryption implementation.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Attackers gain administrative access to gas analyzers, potentially manipulating gas measurements, disrupting industrial processes, or using devices as footholds into industrial control networks.

🟠

Likely Case

Attackers obtain credentials to access device interfaces, potentially viewing sensitive process data or modifying device configurations.

🟢

If Mitigated

With proper network segmentation and access controls, impact is limited to the specific device without lateral movement to other systems.

🌐 Internet-Facing: MEDIUM

🏢 Internal Only: HIGH

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires access to stored credential data and knowledge of weak encryption algorithm.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Contact Emerson for specific firmware updates

Vendor Advisory: https://www.emerson.com/documents/automation/security-notification-emerson-rosemount-x-stream-gas-analyzer-en-7881468.pdf

Restart Required: Yes

Instructions:

1. Contact Emerson support for firmware updates. 2. Apply firmware update following Emerson's instructions. 3. Restart device. 4. Change all credentials after update.

🔧 Temporary Workarounds

Network Segmentation

all

Isolate gas analyzers from untrusted networks using firewalls and VLANs

Credential Rotation

all

Regularly change all device credentials to limit exposure window

🧯 If You Can't Patch

Implement strict network access controls allowing only authorized management stations
Monitor device logs for unauthorized access attempts and credential changes

🔍 How to Verify

Check if Vulnerable:

Check device firmware version against Emerson's advisory and examine if weak encryption is used for credential storage

Check Version:

Check device web interface or serial console for firmware version information

Verify Fix Applied:

Verify firmware version is updated to Emerson's recommended version and test credential encryption

📡 Detection & Monitoring

Log Indicators:

Multiple failed login attempts
Successful logins from unusual IP addresses
Credential changes

Network Indicators:

Unusual network traffic to/from gas analyzer management ports
Brute force attempts on authentication services

SIEM Query:

source="gas_analyzer" AND (event_type="authentication_failure" OR event_type="credential_change")

📊 Metadata

CVE ID: CVE-2021-27457

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CWE: CWE-326

Published: May 20, 2021

Last Updated: November 21, 2024

🔗 References

https://us-cert.cisa.gov/ics/advisories/icsa-21-138-01 Third Party Advisory,US Government Resource
https://us-cert.cisa.gov/ics/advisories/icsa-21-138-01 Third Party Advisory,US Government Resource

📤 Share & Export

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🔗 Related Vulnerabilities

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